Method and apparatus for agricultural engineering.



.n. A. FESSENDEN.

- METHOD AND APPARATUS FOR AGRICULTURAL ENGINEERING. APPLICATION FILEDHim-4.1918.

Patented June 11, 1918.

A. FESSENDEN, 0F BROOKLINE, MASSACHUSETTS.

METHOD AN D APPARATUS FOR, AGRICULTURAL ENGINEERING,

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To all whom it may concern: A

Be it known that I, RIGINALD A. FEs'sEN- DEN, of Brookline, in thecounty of Norfolk and State of Massachusetts, a citizen of the UnitedStates, have invented new and useful Improvements in Methods andApparatus for Agricultural Engineering, of which the following is thespecification.

My invention relates to agricultural engi neering and more particularlyto the growth of plants, and has for its object increased efliciency inagricultural engineeringand more particularly increased production andbetter quality of agricultural products.

The figure accompanying this specification shows partly diagrammaticallysuitable means for carryin out my invention.

That the growt of plants may be influenced by the discharge ofelectricity has been well known formore than a hundred years. It has,however, been found very diflicult to obtain consistentresults and whilein some experiments the electrical discharges have apparently greatlyincreased the rate of growth, in other experiments the effect has beennegligible or even negative.

Applicant, in continuation and extension of this experimental work inagricultural engineering, a portion of which has already been disclosedand claimed in U. S. Patent.

1,121,722, filed October 6, 1906, has discovered new methods andapparatus for influencing the growth of plants by electrical discharges,which appear to give consistent and very favorable results, as. followsIn the figure, 11 is the soil, 12 is the plant whose rate of growth andproduction is to be increased, 13-44 are posts, 15, 16 are insulators,17 is an electrical conductor, 18, 18, 18, 18 are discharge points, 22is a high potential rectifier of any suitable form well" known in theartpreferably a hot cathode t pe-21 is the high potential see'onda of atransformer, connectedto the groun as shown. 7

20 is the primary of the transformer; 19 is an alternating currentdynamo for exciting the transformer; 23, 2 1 are the field leads of thedynamo connected to the rheostat 25, having the axis 27 of its contactarm drlven by the motor 26, so that on the motor 26 turning around, theaxis 27 0f the contact arm of the rheostat 25 also rotates and. the

' resistance of the field circuit 23, 2 1 of the dynamo 19 isperiodically increased and di:

Specification of Letters Patent.

Patented June 11, 1916..

- Application filed February 4,1918. Serial No. 215,358.

By this means, in place of maintaining a steady discharge or anindefinite and irregular discharge or a high frequency discharge fromthe discharge oints 18, 18, 18 18, a definitely periodic scharge and ofrelatively low frequency is obtained, and this method of operationappears to give consistant and favorable results.

Applicant does not know definitely why this method should 've so muchbetter results than the metho s heretofore used. The facts as observedby him are that whe'n the electric discharge is continuous or of highfrequency or irregularly intermittent, the results obtained varyconsiderably; but that when the electric discharge apparatus is arrangedas shown to give a definitely periodic discharge, depending upon thespeed of rotation of the'motor 26, on starting in with a high rate ofdischarge frequency and decreasing the frequenc every few days acritical frequency wi be reached*-wh1ch gives a very rapid increase ofgrowth,.wi1ile frequencieshigher than this frequency givevery muchoorer'and more or less inconsistent resu ts, and frequencies lowerthan-Applicant has found that with most plants there are two or threecritical frequencies; for example, one revolution in four seconds, .onein two and a half seconds and one in one-half second, but the relationof these" critical frequencies to each other has not so far beendetermined.

Applicant has also found that the critical frequency, '01 frequencies,depend upon the kind of plant and upon its age and possibly upon thedistance apart of the'branches of the plant.

Applicant has alsofound that it is sometimes advantageous to arrange thesteps of the rheostat 25 so that the variation of the ti l potential atthe dischargingpoints 18, 18, 18, 18 does not vary as a smooth sinecurve but is, on the contrary, strongly peaked.

Applicant has also found that 1t is sometimes advantageous to haveprolonged periods of rest; i, 6., to operate the apparatus for a numberof hours and then to entirely discontinue the electrical discharges fora,

time.

What applicant claims is: -1. The method of increasing the growth andproduction of plants, which consists in generating an electricaldischarge, controlling said electrical discharge so that said dischargeoccurs at a definite, pre-determined, and relatively low frequency, andplacing said electrical discharge in operative relation to the plantwhose growth is to be influenced, thereby promoting the growth of Saidplants.

- 2. Apparatus for increasing the production'and electrical ischargefield in proximity to said plants and means for varying the intensity ofsaid electrical discharge periodically and at a relatively lowfrequency.

REGINALD A. FESSENDEN.

rowth of plants, comprismg an

